The invention is a fuel cooling device with a cylindrical housing, in this refrigerant tube a tube for the refrigerant is mounted, which is surrounded by a spirally wound fuel tube. Connecting ends are provided for moving the refrigerant and the fuel.
Fuels for vehicles generally have relatively low boiling point and therefore tend to higher temperatures for evaporation of the volatile matters of the fuel. The additives usually evaporate first, due to both, environmental pollution by uncontrolled exhaust of gas and, deteriorated conditions for the engine due to the lack of additives in the fuel. In order to avoid this as well as vapor lock in the fuel system, there are fuel cooling devices, which are applied in connection with air conditioning devices in the vehicle.
A cooling device of the kind mentioned above is described in the DE-GM 8335036.5. Therein a housing of the shape of a tube section is used, in which a tube for the refrigerant is mounted. On the external face of this tube, there is a spirally formed fuel tube assembly, which is formed in connection with the tube section of the housing. In the cross section of the tube for the refrigerant there is a body to swirl the refrigerant. The housing and the tube for the refrigerant are equipped with respective connecting ends. A cooling device of this kind has the disadvantage that the heat leaving the refrigerant has to be led through a relatively small surface, namely the circumferential surface of the tube for the refrigerant. The contact surface to the refrigerant is therefore limited accordingly. The fuel flows in its spirally wound fuel tube assembly directly along the walls of the housing, which the refrigerant does not reach. This has another disadvantage, since, in the case of an accident, the fuel assembly which is located outside might be damaged. This would cause leakage of the fuel. The cooling performance of a device of this kind might be corrected by the respective equipment and dimensions; however, it cannot be adjusted in operation. In order to reach the sealing of the fuel assembly, a brazing procedure with a minimum of two braze joints is necessary, which requires great efforts.
According to the DE-PS3100021 there, is a fuel cooling device for an internal combustion engine. A refrigerant is axially flowing through the housing, whereas the fuel is led over radial connecting ends and axially directed circular gaps through the housing. The circular gaps are formed by two axial convoluted tubes, which are located on both sides of a connecting tube and are connected to each other on one end by openings of the tube. The refrigerant flows around the outer convoluted tube on its outer surface and around the inner convoluted tube on the inside. Although this kind of construction makes a bigger surface for transmitting the heat available, the use of the convoluted tubes requires a lot of braze joints, the production of which requires great efforts and careful processing. It is advantageous the tube for the fuel is already located inside the housing and is flushed by the refrigerant. Capacity control of the cooling device is missing.